Well I use my Express exclusively for listening to podcasts. I got it because it was small, cheap and had an integrated USB connecter. Overall it is satisfactory though I did write my own MTP application to use on Linux (I also had to submit the USB vendor and product ID to the MTP upstream library maintainers) so that I could easily manage the playlists. I do wish I could put simple m3u playlists in some directory in MSC mode and have them picked up like it does with MP3s.
There is no “play once” feature though I would love to have one! There also isn’t a way to delete mp3s or playlist item from the UI, which might give something similar to that kind of feature. My main reason for implementing that homebrew MTP app was so that I could manage podcast playlists how I wanted.
Is the trick of powering off the player while it’s playing a reliable way of resuming? Not really. Mostly it works but quite often is does not. I just got back from a trip back home for an early Christmas and took my Express loaded with various podcasts. My place was lost about a third of the time. And what makes it worse is that the device will auto power off after 2 minutes of inactivity. That time is configurable, but it is reset back to 2 minutes after every power off. That means that if I need to stop it to talk to someone, I pretty much have to turn it off and not pause it. That also means I lose my place frustratingly often.
I just ran a quick test and it appears that it does remember your spot if you use the sleep feature.
I’ve never tried to use the audible features because I am anti-DRM. I suspect there might be a way to trick it into thinking it is an audible book but I’m not sure whether it really buys you much.
For it’s size and price I do think it makes a pretty decent mp3 player for podcasts. Though admittedly I ran across your post because I am researching whether some of the quirks I mentioned would be fixed with a firmware upgrade (it’s a pain to attempt because I run Linux exclusively). FYI it does not appear that a firmware upgrade is going to fix anything, but maybe I’ll do it just to be sure.